This invention relates, in general, to semiconductor components and, more particularly, to scribe seal structures on semiconductor components.
Typically, a plurality of semiconductor components are manufactured from a single semiconductor wafer. The semiconductor wafer is partitioned into a plurality of rectangular regions called die or chips, where adjacent chips are separated by scribe lines. The manufacturing process is designed so all the chips on a single semiconductor wafer are identical. Once the transistor circuitry and associated metal interconnects have been fabricated in the chip active region, the semiconductor wafers are sawed along the scribe lines to separate or singulate the semiconductor wafer into a plurality of semiconductor chips. The chips are then packaged, tested, and shipped to customers.
Sawing or cutting the semiconductor wafer stresses it and causes microcracking to occur. The microcracks can migrate to the active regions of the chips and damage the circuitry fabricated in the semiconductor wafer. To prevent or arrest microcrack migration, designers place scribe seal structures between the active region of the chip and the scribe lines. These structures prevent microcracks formed during sawing along the scribe lines from migrating to the active region, thereby preventing the microcracks from damaging the semiconductor components.
FIG. 1 illustrates an enlarged cross-sectional view of a scribe seal structure 100 in accordance with the prior art. Scribe seal structure 100 comprises a semiconductor substrate 102 having a dielectric layer 104 disposed thereon. Dielectric layer 104 has an opening 106 filled with copper that forms a copper layer 108. A capping layer 110 is disposed on dielectric layer 104 and copper layer 108. A dielectric layer 112 having a plurality of openings 114 is disposed on capping layer 110. Openings 114 extend through capping layer 110 and expose portions of copper layer 108. Openings 114 are filled with copper to form copper-filled vias 115. A dielectric layer 116 having an opening 118 is formed on dielectric layer 112 and copper-filled vias 115. Opening 118 is filled with copper that forms a copper layer 120. A capping layer 124 is disposed on dielectric layer 116 and copper layer 120. A dielectric layer 126 having a plurality of openings 128 is disposed on capping layer 124. Openings 128 extend through capping layer 124 and expose portions of copper layer 120. Openings 128 are filled with copper to form copper-filled vias 129. A dielectric layer 132 having an opening 134 is formed on dielectric layer 126 and copper-filled vias 129. Opening 134 is filled with copper that forms a copper layer 135. A capping layer 136 is disposed on dielectric layer 132 and copper layer 135. A dielectric layer 137 having a plurality of openings 138 is disposed on capping layer 136. Openings 138 extend through capping layer 136 and expose portions of copper layer 135. Openings 138 are filled with copper to form copper-filled vias 139. A dielectric layer 140 having an opening 141 is formed on dielectric layer 137 and copper-filled vias 139. Opening 141 is filled with copper that forms a copper layer 142. A capping layer 144 is disposed on dielectric layer 140 and copper layer 142. A drawback of scribe seal structure 100 is that openings 114, 128, and 138 are formed using Reactive Ion Etching (RIE) that terminates on copper. Because these openings terminate on copper, the RIE causes sputtering of the copper from copper layers 108, 120, and 135, that are exposed by openings 114, 128, and 138, respectively. As those skilled in the art are aware, copper is a silicon contaminant. Thus, the sputtered copper contaminates the silicon substrate which leads to device failure.
Accordingly, what is needed is method and structure for forming scribe seals that does not cause copper to be sputtered.
The present invention satisfies the foregoing need by providing a scribe seal, a method for fabricating the scribe seal, and a semiconductor component including the scribe seal. In accordance with one aspect of the present invention, the scribe seal comprises a semiconductor substrate having a crack arrest structure disposed on a first portion of a major surface. A dielectric layer is disposed on a second portion of the major surface, where the dielectric layer is adjacent the crack arrest structure. Another crack arrest structure is disposed on the dielectric layer that is disposed on the major surface. This crack arrest structure is laterally spaced apart from the crack arrest structure disposed on the major surface. The crack arrest structures cooperate to form a scribe seal.
In accordance with another aspect, the present invention includes a method for manufacturing a scribe seal. A semiconductor substrate having a major surface is provided. A layer of dielectric material is disposed on a portion of the major surface and an opening is formed in the layer of dielectric material to expose a portion of the major surface. The opening is filled with a crack arresting material to form a crack arrest structure. A layer of dielectric material is formed on the crack arresting material and the layer of dielectric material disposed on the major surface. An opening is formed in the second layer of dielectric material, which opening exposes a portion of the first layer of dielectric material. The opening in the second layer of dielectric material is filled with crack arresting material to form a crack arrest structure. The crack arrest structures cooperated to form a scribe seal.
In accordance with yet another aspect, the present invention includes a semiconductor component having a scribe seal in accordance with an embodiment of the present invention.